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Effect of CXL on FS laser Channel Creation for ICR in KC. Tamer M. El-Raggal, MD, PhD, FRCSEd Associate Professor of Ophthalmology Ain Shams University, Cairo - Egypt. No Financial Interest. El- Raggal , T. Introduction. Studies demonstrated efficacy of ICRS → improvement of KC.
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Effect of CXL on FS laser Channel Creation for ICR in KC Tamer M. El-Raggal, MD, PhD, FRCSEd Associate Professor of Ophthalmology Ain Shams University, Cairo - Egypt No Financial Interest
El-Raggal, T Introduction • Studies demonstrated efficacy of ICRS → improvement of KC. • CXL ↑ mechanical stiffness → stabilization of KC • FS laser photodisruption → separate tissue at molecular level without impact on surrounding tissue. • Combination of 3 modalities provide better results as they complement each other.
El-Raggal, T Aim of the Study • To evaluate efficacy of FS laser for channel creation after CXL in KC eyes. • Inclusion criteria • CL intolerance. • Clear cornea. • Maximum K < 60 D. • Minimum thickness > 450 µm. • CXL done 6 m before.
El-Raggal, T Patients & Methods • A prospective non-randomized study included 15 eyes of 11 patients with II-III KC (Amsler- Krumeich) treated by CXL → 6 m later channel creation using Intralase FS 60. • Group 1 5 eyes → 1.50 mJ • Group 2 5 eyes → 1.60 mJ • Group 3 5 eyes → 1.70 mJ • Control 5 virgin KC eyes → 1.50 mJ
El-Raggal, T Corneal Channels Creation • Axis → steep topography. • 80% depth. • Inner diameter 5.0 & outer 5.8 mm. • Entry cut thickness 1 µm. • Incision length 1.40 mm. • Ring energy 1.50 – 1.70 mJ. • Spot separation Default. • Implantation immediately before bubbles disappear using forceps.
El-Raggal, T Keraring Insertion • ICR insertion graded subjectively • 0 = Easy, no resistance • 1+ = Slight resistance • 2+ = Moderate resistance, some manual separation • 3+ = Difficult, severe resistance, all manual dissection • Corneal haze quantified subjectively on slit lamp 0 = No haze, totally transparent 1+ = Slight corneal haze, slight loss of transparency 2+ = Moderate haze. iris details seen 3+ = Exaggerated haze, iris details hardly seen
El-Raggal, T Results Difficulty
El-Raggal, T Results Haze
El-Raggal, T • Incomplete tunnel creation is most common difficulty of FS laser • Tissue bridges in tunnel may resist ICRS implantation. • Although channel creation & segment implantation can be done without changing FS parameters, it is better to ↑ energy. • Resultant ↑ corneal reaction postoperatively.
El-Raggal, T Conclusion • CXL causes compactness of stromal lamellae in superficial 300 µm but deeper stroma also affected to some extent • Also CXL cornea less clear than normal → FS laser penetration less effective.
El-Raggal, T Conclusion • FS channel creation can be performed safely after CXL. • Better to perform channel dissection before or concurrent to CXL → More improvement in corneal shape by ICR. • Limitations: Non-randomized, small sample, subjective grading of difficulty & haze. • Further studies with larger samples & studying effect of spot separation recommended.